CVE-2026-12537: Gemini CLI RCE and Claude Code Secret Leak
Novee Security demonstrated at Black Hat USA 2026 that default configurations of Gemini CLI, Claude Code, and OpenAI Codex allowed a GitHub issue from an unprivileged account to trigger code execution on CI runners and exfiltrate API secrets. Two CVEs were issued: CVE-2026-12537 (CVSS 10.0) for an OS command injection in Gemini CLI's container launcher, and CVE-2026-54316 for a covert API key exfiltration channel in Claude Code. The root cause across all three agents was insecure harness logic — the code layer mediating between the LLM and the host system — rather than the models themselves.